A pedagogical introduction to some of the main ideas and results of field theories on quantized s... more A pedagogical introduction to some of the main ideas and results of field theories on quantized spacetimes is presented, with emphasis on what such field theories may teach us about the problem of quantizing gravity. We examine to what extent noncommutative gauge theories may be regarded as gauge theories of gravity. UV/IR mixing is explained in detail and we describe its relations to renormalization, to gravitational dynamics, and to deformed dispersion relations in models of quantum spacetime of interest in string theory and in doubly special relativity. We also discuss some potential experimental probes of spacetime noncommutativity.
in unconformity proximal and fracture controlled types of uranium mineralisation in Koppunuru are... more in unconformity proximal and fracture controlled types of uranium mineralisation in Koppunuru area, Guntur district, Andhra Pradesh, India using beta-gamma and gamma-ray spectrometry techniques on mineralised borehole core samples.
Chenchu colony area, Guntur district, Andhra Pradesh, is targeted for sub-surface exploration bas... more Chenchu colony area, Guntur district, Andhra Pradesh, is targeted for sub-surface exploration based on favourability criteria for Proterozoic unconformity-related fracture-controlled uranium mineralisation. Geologically, Neoarchaean to Palaeoproterozoic granitoids form basement for the overlying Neoproterozoic Kurnool Group of sediments (Banganapalle and Narji Formations). These granitoids are substantially reactivated in nature as evident from the presence of fractures/faults, mafic dykes and quartz/ quartzo-feldspathic veins. Geochemically, they (n=17) show wide variation in SiO 2 (68.12–76.65%), Al 2 O 3 (11.34–17.29%), K 2 O (4.30–9.96%), Na 2 O (0.21–3.14%) and CaO (0.08–3.87%) contents while two highly altered and radioactive granitoids (171 and 445 ppm U) exhibit comparatively low average abundance of SiO 2 (64.54%) and high abundance of Al 2 O 3 (18.56%) and K 2 O (7.96%). Total alkali content of these granitoids varies from 7.13 to 10.17% with an overall predominance of potassium over sodium. They belong to granite–adamellite suite and exhibit a predominant peraluminous nature (A/CNK: 1.01–1.87; except for three samples with values of 0.67–0.95), signifying derivation of the magma from sedimentary or supracrustal sources with S-type signature. This is further substantiated by low sodium (<3.2% Na 2 O) and high potash (~5% K 2 O) contents as well as sample plots in Altherr's diagram [mol CaO/(MgO+FeO t) vs mol Al 2 O 3 /(MgO+FeO t)], indicating generation of these granitoids by partial melting of metapellitic (crustal) sources. Petrographic evidences viz., presence of K–feldspar (orthoclase, microcline), both varieties of mica (muscovite and biotite), monazite and apatite support the above observation. In Rb–Nb+Y and Nb–Y tectonic discrimination plots, these granitoids straddle in the fields of volcanic arc granite (VAG) and syn-collision (syn-COLG), signifying evolution in subduction-related arc magmatism in a collisional environment, which is further corroborated by sample plots in syn-collision field in R1–R2 diagram. Such reactivated S-type granitoids with high intrinsic uranium (19ppm U) form a potential and fertile source, which may lead to uranium mineralisation under favourable conditions in an unconformity proximal setup.
Disequilibrium studies were attempted on mineralised core samples (n=870) from Koppunuru uranium ... more Disequilibrium studies were attempted on mineralised core samples (n=870) from Koppunuru uranium deposit located in south-western part of Palnad sub-basin, Guntur district, Andhra Pradesh, India. The area exposes Banganapalle quartzites unconformably deposited over altered biotite granite (basement). Uranium mineralisation in Koppunuru deposit is hosted by Banganapalle quartzites well above the unconformity, and grit/basement granite close to the unconformity contact. For disequilibrium studies, the core samples were broadly divided in two groups, (a)quartzite hosted (above unconformity) and (b) basement granite hosted mineralisation (below unconformity). Average disequilibrium factor of 41% has been recorded in favour of parent uranium in both types of core samples. It shows significant enrichment of uranium in the system as evident from 41% of disequilibrium in favour of parent uranium. This is probably due to significant migration of some of the daughter radio nuclides due to dissolution of minerals by groundwater action. Besides, the escape of radioactive radon might have accentuated the disequilibrium factor thus increasing the grade of uranium mineralization. The presence of fractures and faults in the study area are the probable conduits for radon migration/escape. Linear regression coefficient between uranium and radium is 0.98 indicates invariability of disequilibrium irrespective of grade.
Hydrogeochemical exploration was undertaken over an area of 3100 km 2 in the northeastern part of... more Hydrogeochemical exploration was undertaken over an area of 3100 km 2 in the northeastern part of Cuddapah Basin to identify target areas for exploring the unconformity-related U-mineralization. Water samples from 626 borewells drilled in the Kurnool Group of the Palnadu sub-basin, Nallamalai Group and basement rocks were collected. For the individual lithological domain, univariate and multivariate statistical techniques were applied to the analytical data on 20 variables, i.e. U, Na, K, Ca, Mg, Cl, SO 4 , HCO 3 , CO 3 , Si, Fe, Cu, Ba, Zn, F, Mn, conductivity, total dissolved salts (TDS), Eh and pH. The R-mode factor analysis establishes geochemical association between U, Na, K, Cl, SO 4 , HCO 3 , TDS and conductivity. Another important association is between Fe, Mn and Zn. Maps of factor-1 scores (with high loadings on U) and U-contours, clearly delineate the well-established U-mineralization at Koppunuru -Dwarkapuri in the Palnadu sub-basin. Interestingly, the same maps also display another prominent north -south trending anomaly zone extending over a linear stretch of 45 km, commencing in the basement, passing through the Nallamalai Group and continuing into the younger Kurnool Basin in the eastern part. The hydrogeochemical anomaly around Julakallu is significant for targeting unconformity-related U-mineralization as, in this area, the Kurnool Group sediments unconformably overly the most promising Cumbum Formation comprising low-grade metamorphosed carbonaceous pelites. D
A pedagogical introduction to some of the main ideas and results of field theories on quantized s... more A pedagogical introduction to some of the main ideas and results of field theories on quantized spacetimes is presented, with emphasis on what such field theories may teach us about the problem of quantizing gravity. We examine to what extent noncommutative gauge theories may be regarded as gauge theories of gravity. UV/IR mixing is explained in detail and we describe its relations to renormalization, to gravitational dynamics, and to deformed dispersion relations in models of quantum spacetime of interest in string theory and in doubly special relativity. We also discuss some potential experimental probes of spacetime noncommutativity.
in unconformity proximal and fracture controlled types of uranium mineralisation in Koppunuru are... more in unconformity proximal and fracture controlled types of uranium mineralisation in Koppunuru area, Guntur district, Andhra Pradesh, India using beta-gamma and gamma-ray spectrometry techniques on mineralised borehole core samples.
Chenchu colony area, Guntur district, Andhra Pradesh, is targeted for sub-surface exploration bas... more Chenchu colony area, Guntur district, Andhra Pradesh, is targeted for sub-surface exploration based on favourability criteria for Proterozoic unconformity-related fracture-controlled uranium mineralisation. Geologically, Neoarchaean to Palaeoproterozoic granitoids form basement for the overlying Neoproterozoic Kurnool Group of sediments (Banganapalle and Narji Formations). These granitoids are substantially reactivated in nature as evident from the presence of fractures/faults, mafic dykes and quartz/ quartzo-feldspathic veins. Geochemically, they (n=17) show wide variation in SiO 2 (68.12–76.65%), Al 2 O 3 (11.34–17.29%), K 2 O (4.30–9.96%), Na 2 O (0.21–3.14%) and CaO (0.08–3.87%) contents while two highly altered and radioactive granitoids (171 and 445 ppm U) exhibit comparatively low average abundance of SiO 2 (64.54%) and high abundance of Al 2 O 3 (18.56%) and K 2 O (7.96%). Total alkali content of these granitoids varies from 7.13 to 10.17% with an overall predominance of potassium over sodium. They belong to granite–adamellite suite and exhibit a predominant peraluminous nature (A/CNK: 1.01–1.87; except for three samples with values of 0.67–0.95), signifying derivation of the magma from sedimentary or supracrustal sources with S-type signature. This is further substantiated by low sodium (<3.2% Na 2 O) and high potash (~5% K 2 O) contents as well as sample plots in Altherr's diagram [mol CaO/(MgO+FeO t) vs mol Al 2 O 3 /(MgO+FeO t)], indicating generation of these granitoids by partial melting of metapellitic (crustal) sources. Petrographic evidences viz., presence of K–feldspar (orthoclase, microcline), both varieties of mica (muscovite and biotite), monazite and apatite support the above observation. In Rb–Nb+Y and Nb–Y tectonic discrimination plots, these granitoids straddle in the fields of volcanic arc granite (VAG) and syn-collision (syn-COLG), signifying evolution in subduction-related arc magmatism in a collisional environment, which is further corroborated by sample plots in syn-collision field in R1–R2 diagram. Such reactivated S-type granitoids with high intrinsic uranium (19ppm U) form a potential and fertile source, which may lead to uranium mineralisation under favourable conditions in an unconformity proximal setup.
Disequilibrium studies were attempted on mineralised core samples (n=870) from Koppunuru uranium ... more Disequilibrium studies were attempted on mineralised core samples (n=870) from Koppunuru uranium deposit located in south-western part of Palnad sub-basin, Guntur district, Andhra Pradesh, India. The area exposes Banganapalle quartzites unconformably deposited over altered biotite granite (basement). Uranium mineralisation in Koppunuru deposit is hosted by Banganapalle quartzites well above the unconformity, and grit/basement granite close to the unconformity contact. For disequilibrium studies, the core samples were broadly divided in two groups, (a)quartzite hosted (above unconformity) and (b) basement granite hosted mineralisation (below unconformity). Average disequilibrium factor of 41% has been recorded in favour of parent uranium in both types of core samples. It shows significant enrichment of uranium in the system as evident from 41% of disequilibrium in favour of parent uranium. This is probably due to significant migration of some of the daughter radio nuclides due to dissolution of minerals by groundwater action. Besides, the escape of radioactive radon might have accentuated the disequilibrium factor thus increasing the grade of uranium mineralization. The presence of fractures and faults in the study area are the probable conduits for radon migration/escape. Linear regression coefficient between uranium and radium is 0.98 indicates invariability of disequilibrium irrespective of grade.
Hydrogeochemical exploration was undertaken over an area of 3100 km 2 in the northeastern part of... more Hydrogeochemical exploration was undertaken over an area of 3100 km 2 in the northeastern part of Cuddapah Basin to identify target areas for exploring the unconformity-related U-mineralization. Water samples from 626 borewells drilled in the Kurnool Group of the Palnadu sub-basin, Nallamalai Group and basement rocks were collected. For the individual lithological domain, univariate and multivariate statistical techniques were applied to the analytical data on 20 variables, i.e. U, Na, K, Ca, Mg, Cl, SO 4 , HCO 3 , CO 3 , Si, Fe, Cu, Ba, Zn, F, Mn, conductivity, total dissolved salts (TDS), Eh and pH. The R-mode factor analysis establishes geochemical association between U, Na, K, Cl, SO 4 , HCO 3 , TDS and conductivity. Another important association is between Fe, Mn and Zn. Maps of factor-1 scores (with high loadings on U) and U-contours, clearly delineate the well-established U-mineralization at Koppunuru -Dwarkapuri in the Palnadu sub-basin. Interestingly, the same maps also display another prominent north -south trending anomaly zone extending over a linear stretch of 45 km, commencing in the basement, passing through the Nallamalai Group and continuing into the younger Kurnool Basin in the eastern part. The hydrogeochemical anomaly around Julakallu is significant for targeting unconformity-related U-mineralization as, in this area, the Kurnool Group sediments unconformably overly the most promising Cumbum Formation comprising low-grade metamorphosed carbonaceous pelites. D
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disequilibrium factor of 41% has been recorded in favour of parent uranium in both types of core samples. It shows significant enrichment of uranium in the system as evident from 41% of disequilibrium in favour of parent uranium. This is probably due to significant migration of some of the daughter radio nuclides due to dissolution of minerals by
groundwater action. Besides, the escape of radioactive radon might have accentuated the disequilibrium factor thus increasing the grade of uranium mineralization. The presence of fractures and faults in the study area are the probable conduits for radon migration/escape. Linear regression coefficient between uranium and radium is 0.98 indicates
invariability of disequilibrium irrespective of grade.
disequilibrium factor of 41% has been recorded in favour of parent uranium in both types of core samples. It shows significant enrichment of uranium in the system as evident from 41% of disequilibrium in favour of parent uranium. This is probably due to significant migration of some of the daughter radio nuclides due to dissolution of minerals by
groundwater action. Besides, the escape of radioactive radon might have accentuated the disequilibrium factor thus increasing the grade of uranium mineralization. The presence of fractures and faults in the study area are the probable conduits for radon migration/escape. Linear regression coefficient between uranium and radium is 0.98 indicates
invariability of disequilibrium irrespective of grade.